1. Field of the Invention
The present invention relates to modifying reagents and modified organic media treated hereby, and more particularly to modifying reagents for making natural organic materials into the modified organic media, which are appropriate for planting trees and flowers, and to modified organic media being made thereby to be used in the planting fields of civil engineering works such as agriculture, forestry, gardening, and landscape design.
2. Background Art
Conventionally, materials to be used for cultivating trees and flowers include peat moss, coconut dusts (simple coconut dust, and those containing coconut staple fibers or coconut pericarp chips), tuff loam aggregates, perlite, beaten bark, and sawdust.
Of these, coconut dusts, beaten bark, and sawdust are hard to be biodegraded despite of being organic, and have excellent properties such as low water-repellency in dried state and high water/fertilizer retention capacities, which no other natural organic material has. On this account, recently, large amount of these materials have been used as the organic media for plant culture.
However, the natural organic materials obtained from the coconut dusts and the beaten bark contain a lot of salt (NaCl), which adversely affects the cultivation of plants. In order to remove the contained salt, the coconut dusts require some treatment of being exposed outdoor over a long period, e.g., 5 to 10 years, or immersed in water. Therefore, the preparation of the appropriate natural organic media take quite long time, leading to a limit in amount of supply.
Meanwhile, in addition to the aforesaid salt, the natural organic materials obtained from the coconut dusts, beaten bark and sawdust contain a large amount of organic acids such as phenolic acids, which also adversely affect the cultivation of plants. Especially, untreated coconut dusts with in about one to two years after harvest contain a great quantity of organic acids, and are inappropriate for the natural organic materials for cultivating plants. As well as the aforesaid salt, the organic acids can be removed by treatment of the long-term exposure or the water-immersing. However, there lies a problem of the same sort as in the salt.
Besides, an increase in demanded amount of the natural organic materials obtained from the coconut dusts, beaten bark and sawdust produces a problem of a decreasing supply of long-term-exposed coconut dusts. On this account, it has been desired to prepare new organic media from a large stock of untreated coconut dusts by some simple treatment without the long-term exposure.
The coconut dusts to be used in the present invention are harder to be biodegraded than peat moss that is known as the hardest material to be biodegraded among natural organic materials. The biodegradation of the natural organic materials by microorganisms causes nitrogen starvation or development of reduction state inside the natural organic materials themselves; therefore, additional lowering of the biodegradability is required. Note that, in the present invention, coconut dusts used is both simple coconut dust, and those containing coconut staple fibers or coconut pericarp chips.
In view of the foregoing problems, an object of the present invention is to provide modifying reagents for treating the natural organic materials obtained from coconut dusts, beaten bark and sawdust, which are capable of changing the organic media so as to prevent the adverse effects on the cultivation of plants. Note that, in the present invention, the beaten barks mean barks of both broadleaf trees and needleleaf trees.
Another object of the present invention is to provide the modifying reagents for decreasing the biodegradability of the natural organic materials obtained from the coconut dusts, beaten bark and sawdust. In other words the modified organic media of the present invention are substantially not microbially decomposed.
Besides, still another object of the present invention is to provide the modified organic media prepared from coconut dusts, beaten bark, sawdust by the aforesaid modifying reagents.
As an aspect of the present invention, the modifying reagents comprises at least one salt selected from among iron salts and aluminum salts. Here, the organic materials to be treated with the modifying reagents are preferably coconut dusts, beaten bark, and sawdust.
By means of the modifying reagents the organic acids contained in the coconut dusts are chemically reacted with the Fe and/or Al ions in the reagents to become insoluble, thereby enabling the removal of the obstacles to the cultivation of plants. At the same time, the biodegradability of the natural organic materials is remarkably suppressed; that is to say, the modified organic media are substantially not microbially decomposed.
Besides, the cations of the modifying reagents seem to have displacing effect on the sodium salt, which hampers the cultivation of plants, to promote desalting.
As another aspect of the present invention, the modified organic media are provided by treating the natural organic materials with the modifying reagents containing at least one salt selected from among the iron salts and the aluminum salts. Here, the organic materials are preferably coconut dusts, beaten bark, and sawdust.
Treatment using the modifying reagents of the present invention eliminate obstacles to the cultivation of plants even in the untreated coconut dusts. Here, well-balanced nutrients can be added to obtain modified organic media well suitable for cultivating plants.
Reagents for treating natural organic materials according to the present invention (called [xe2x80x9cmodifying reagentsxe2x80x9d]) comprises at least one type of metallic salt. The metallic salt is selected from among iron salts and aluminum salts. Any one of these salts may be used alone, or in combination. In the present invention, iron salts are preferably used since the resulting modified organic media treated thereby are wider in usable pH range.
Examples of the aforesaid iron salt are ferrous sulfate, ferric sulfate, ferrous chloride, ferric chloride, ferrous nitrate, ferric nitrate, and mixtures thereof. Examples of the aluminum salts are aluminum sulfate, aluminum chloride, and mixtures thereof. Of these, ferrous sulfate and ferric sulfate are preferable. Ferrous sulfate is the most preferable.
Natural organic materials can be treated with the aforesaid modifying reagents to be changed into modified organic media according to the present invention. The natural organic materials in the present invention are preferably obtained from coconut dusts (simple coconut dust, or those containing coconut staple fibers, coconut pericarp chips), beaten bark, sawdust. As for bark, that of both broadleaf trees and needleleaf trees may be treated by the aforesaid modifying reagents into the modified organic media of the present invention. Besides, the modifying reagents of the present invention can be effective for previously desalted natural organic materials also. Note that, in the present invention, untreated coconut dust means the organic acid rich and non-desalted coconut dust left less than one to two years or so after harvest.
In treating natural organic materials with the modifying reagents of the present invention, the modifying reagents of any form can be used for the treatment. In view of simple treatment processes, that in the form of aqueous solution or powder is preferably used.
The modifying reagents of the present invention range in an applied amount of preferably from 0.1 to 5.0 g, more preferably from 0.3 to 2.0 g, and the most preferably from 0.37 to 0.50 g for 100 g (in dry weight) of the organic materials. At amounts of application smaller than 0.1 g, the modifying reagents change the organic materials incompletely. On the other hand, at amounts of application greater than 5.0 g, the modifying reagents easily causes phosphorous deficiency in the organic media, which is also unpreferable.
In the form of aqueous solution, the modifying reagents is preferably used at a concentration of from 0.04 to 5% by weight, more preferably from 0.04 to 2% by weight, and the most preferably from 0.06 to 0.2% by weight.
In using the powder of the modifying reagents, an appropriate amount of water is preferably added before, after, or in mixing. The amount of water to be added is not less than 100 ml, and preferably 200 to 300 ml for 100 g of the natural organic materials (in dry weight).
The modified organic media are prepared by a few processes; the desalting process, the modifying reagents adding process, the mixing process, the water adding process, the leaving process, and the compressing process. The modifying reagents may be applied in any of these processes except the compressing process, and is preferably applied before the mixing process. The processes before the mixing process may be performed simultaneously. The desalting process may be omitted.
In the modified organic media of the present invention, plants can be cultivated in the same way as in any conventionally-used organic media. Therefore, conventionally-used additives such as any other natural organic fertilizers and chemical fertilizers may be added to the modified organic media of the present invention.